Sleep problems increase with age. The goal of this Program Project is to understand the nature of the[unreadable] changes in the underlying sleep regulatory processes in older people and the consequences on waking[unreadable] functions such as alertness and cognitive performance, as well as on metabolic functions that may result in[unreadable] age-related diabetes and cardiovascular disease. As part of this program, three related research projects[unreadable] are proposed that require quantitative assessment of sleep and wakefulness. Polysomnography (PSG) is[unreadable] the gold standard for such assessments. We have therefore developed a plan for the creation of a PSG[unreadable] Core in support of the three projects to ensure the accurate and efficient acquisition, analysis and[unreadable] interpretation of PSG derived measures of sleep and wakefulness. In recent years, PSG methodology has[unreadable] undergone dramatic changes that now allow for the collection and analysis of large digitized data sets.[unreadable] Moreover, these developments have resulted in a high degree of sophistication of PSG hardware and[unreadable] software that require a team of specialists who operate and maintain these tools. The general objective of[unreadable] the proposed PSG Core is to provide a knowledge base and an integrated infrastructure in support of three[unreadable] of the projects as well as the Analytic Core within the program. More specifically, the PSG Core will have the[unreadable] following objectives:[unreadable] 1. Acquisition and maintenance of PSG equipment and supplies;[unreadable] 2. Training of technical research staff in equipment use and instrumentation of research subjects for PSG;[unreadable] 3. Archival of digitized PSG data;[unreadable] 4. Vigilance state scoring of PSG recordings, and scoring of attention failures in wake recordings;[unreadable] 5. Quantitative analysis of the sleep and wake EEG with Fast Fourier Transform routine based spectral[unreadable] analysis in order to obtain measures of homeostatic sleep pressure and the circadian drive for sleep.[unreadable] Core C will enable and coordinate the utilization of shared facilities, equipment, and personnel. The Core[unreadable] will at the same time ensure standardized quality control criteria for the acquisition, analysis and[unreadable] interpretation of the data in all three projects. The data will be collected by trained PSG technicians of Core[unreadable] C, and GCRC technicians supervised by Core C staff. Core C will furthermore be responsible for the[unreadable] vigilance state scoring and quantification of the EEG with spectral analysis. This work will be carried out by[unreadable] a PSG technician of Core C, under close supervision of the Core Leader.